23 thoughts on “And Now For Something Completely Different”

    1. O’Neill thought electric power generation would be motivator enough. Back in the 70’s it would have been hard to conceive that in fact AI data-centers might be the driving factor…

      1. It’s going to be a huge mistake. In “The Matrix”, we’d fought the A.I.’s by using nukes to blot out the sun with a global cloud layer, but if the A.I.’s are powered by giant solar arrays in geosynchronous orbit, we’re doomed!

        On a more serious note, the Pentagon should take a deep look at the plans to assess vulnerability to bad actors. We shouldn’t create a big grid vulnerability, especially one that might take a decade or two to fully replace. And of course another issue is disposal. From a delta V perspective, it’s probably easier to boost old components out into the solar system than get them back down to the Earth’s atmosphere.

        1. The bad actors will likely put their grid in space too. My big fear is Carrington 2: Electric Boogaloo or other natural disasters.

          I have been contemplating writing an article on that subject to submit to The Space Review but I have to finalize, submit and get accepted my: “On Horse Poop and Rockets” piece first.

          1. I’m very much with you on the Carrington 2 thing. I wonder just how resistant giant GEO SPSes can be made to such events? Space weather monitoring should allow some modest amount of warning – enough, I think, to allow whatever palliative countermeasures are in place to be activated. I think a transmission outage lasting at least a bit longer than the event would be inevitable, but if actual damage could be avoided and power beaming quickly restored that would be tolerable. The bigger problem might well be on the ground, though even there, some warning could allow damage-limiting steps to be taken.

            I don’t worry overmuch about what bad actors would do. It is my opinion that there won’t be any more bad actors with space launch capability extant by the time GEO SPSes could reasonably be a thing.

            All of that said, I still seriously question the economic case for GEO-based SPS. Ground-based baseload generating capacity is typically built with a design lifetime of at least 30 – 50 years. The only spacecraft ever built that have demonstrated such lifespans are the Voyagers. And the Voyagers are not the size of small counties.

            Even with Starships and New Glenn 9x4s, I’m not confident the financial case for GEO SPS closes. It probably does close for space-based AI data centers because that is an appreciably higher value-add use case than just plain old power generation.

            Where the economics of SPSes may be a much better fit than for Earth would be the Moon, Mars, Mercury, Venus and perhaps even some of the larger Main Belt asteroids.

          2. One nice thing about copper landlines is they were pretty resilient.

            Got ham radio – just in case?

          3. Copper land lines are actually the most vulnerable to things like EMPs and Carrington events. Pretty much the longer a given conductance path, the worse the damage is going to be at each end.

        2. If SMRs come on-line in a big way in a few years or fusion (yeah right, in 20 years) then i don’t see much need for SPS for electric power generation. AI in space is another matter. OTOH the comms bottleneck would need to be solved as well. Through inter-satellite links as well as Space to Ground. I think Musk thinks that can be solved by scaling up Starlink.

    2. Power enables many things that are now in the realm of science fiction, including one idea I have been tormented with making the case close on for decades.

  2. I’m getting:
    “This page is not supported.
    Please visit the author’s profile on the latest version of X to view this content.”

    2. Click the author’s name link and it’s the first post (as of today) – obviously from the comments, it’s about solar power satellites.

    3. You have to click on the link at the bottom of the tweet that looks like a date, not the one in the body.

  3. The one thing I’ve never seen even addressed in SPS discussions where the transmission mechanism is microwave is the interaction of the beam with the ionosphere. A number of projects have been done to study any interactive phenomena, including HAARP and EISCAT. Radio waves in various parts of the spectrum were and are used to excite the electrons in the ionosphere, and a variety of physical quantities measured in order to gain some kind of insight into what happens. The highest power density was HAARP at about 0.03 W/m^2. Effects are small, but measurable. Now, to be useful but not too dangerous, a SPS microwave beam would have to have an intensity of about 130 W/m^2 – this would make the land use on the ground equivalent to the average solar farm. Furthermore, it would have to carry a total of 1,250 MW to be equivalent to a large central power plant. No one has any idea what the effect(s) on the ionosphere would be, or how disruptive to all other RF communications it may prove. For that matter, even the degree of scattering and dissipation is unknown. One thing is certain, and that is that the non-linearity of the plasma dynamics means that no one could just extrapolate from 0.03 W/m^2 and 9.6 MW total power to 4,333 times the power density and 130 times the total power the effects we have measured so far.

      1. Microwave frequencies can be chosen that vapor droplets are relatively transparent to.

        Less sure about IR lasers, but they must have good frequencies to pick, given how much discussion they get.

        I prefer microwaves.

  4. Peter Beck did an interview with the Motley Fool a few months ago that didn’t go into this, but did allude to it, and was a good insight into his ambitions for the company.

    The best development over the last few decades are space related companies who have a mission beyond meeting the details of a government contract.

  5. For space based solar to be viable as an alternative to ground-based solar, the cost of lifting the structure to orbit and assembling it, plus assembling the ground-based structure, must be less than assembling the ground-based equivalent.

    Even Starship when it’s up and running is unlikely to make launch cost cheap, just less expensive. Think shipping something to Australia as being pretty much the physics-based floor to that cost.

    It may end up being cheaper for some locations because the amount of backing reliable power varies somewhat for ground-based solar. For instance, ground-based solar in England pretty much needs backup that will last a week or two, since there’s regularly periods in winter where there’s a couple of weeks with little sun.

    Space-based solar seems more like a solution to power requirements *in space*, than beaming it to Earth.

    Among other things, unless there’s been progress I don’t think anyone’s actually beamed power down for long periods or a lot of it. Scaling up from “running a light bulb for a minute or two” to e.g. “running a 1MW motor for a month” still needs to be done as far as I know. There are failure modes that only happen during this process. I notice there’s still arguments upthread over the frequencies to use; if anyone has done those experiments we would know instead of speculating.

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